Finger sucking, always hunger?

Izabella22

Everytime I take DS out somewhere people say "Oh he's sucking his fingers, must be hungry" - even if I just fed him. He does this a lot and he's great at getting his fingers to his mouth even early on, I assumed some of it was self soothing... he also chews on everything and drools constantly. I keep checking to see if there are signs of teeth coming in but nothing yet... So are these people right is he really hungry? The kid has gained weight like a tank... he's already 19lbs. And I feed him every 3-4 hrs during the day (unless I can tell he's hungry earlier or got distracted at a previous feeding) and doesn't seem hungry after I burp him. Am I crazy... or is sucking the fingers always hunger?  He's happy most of the time and at night when he's hungry he lets me know, but he doesn't have a "hunger cry" that I can tell.